Injury Severity Score
The Injury Severity Score (ISS) is an overall scoring system for patients with multiple injuries. Each injury is assigned an Abbreviated Injury Scale (AIS) score. The highest AIS scores for each of six regions is noted (head, face, chest, abdomen, extremities/pelvis, external).
The scores for the three most severely injured body regions have their scores squared and then added together to produce the ISS score. The ISS score has values between 0 to 75. If any injury is assigned an AIS of 6 (unsurvivable injury) then the ISS score is declared to be 75. Scores between 25 and 40 indicate severe injury. The ISS score correlates with mortality, morbidity, hospital stay and other measures of trauma severity.
The Trauma.org website contains an ISS calculator.
Reference
Baker SP, O'Neill B, Haddon W Jr, Long WB. The Injury Severity Score: A Method for Describing Patients With Multiple Injuries and Evaluating Emergency Care. J Trauma 1974; 14: 187-196.
